This core will provide centralized services to the individual research projects in this Program Project and will also provide reagents needed by several investigators. The core will provide well-characterized stocks of cultured mouse keratinocytes, and provide expertise for subcloning (nested deletions) and template purification for DNA sequencing. A plasmid bank will be maintained to allow all investigators access to appropriate expression vectors and DNA probes, TGF-beta and EGF will be purchased in bulk quantities and stored by the core facility. The core will also prepare tissue culture media, bacterial culture media, agar plates, and sterilize and bake glassware.